Telephone receivers differ in their features. Some manufacturers produce telephones suited for business users that provide robust productivity applications, such as conference schedulers and email clients. Other manufacturers make telephones suited for entertainment that come with entertainment applications, such as video games. When a user wants to buy a telephone receiver, he or she has to choose between having either the productivity applications provided by one manufacturer or the entertainment applications provided by another.
The need to make such choice can be avoided by using hardware virtualization. Both the operating system of the business telephone and the operating system of the entertainment telephone can execute on the same device concurrently, if hardware virtualization is used. This way, when at work, the user can access the productivity applications needed for his or her work on the “business operating system.” And when at home, the user can use the entertainment applications running on the “entertainment operating system.”
However, a significant drawback of present virtualization techniques is that virtualized telephone receivers cannot switch between operating systems seamlessly. If the user receives a business-related call at home, the user will not be able to answer the call and then switch to the business operating system without terminating the call first. The connection has to be terminated because, in general, virtualized operating systems running in a virtualized environment are isolated from each other.
In order for the telephony application executing on the business operating system to be able to take control over the telephone call, it needs at least some information about the phone call state, such as identity of the far-end party, media type used for the phone call (e.g. video, voice, etc.), and so forth. This information, while readily accessible from the entertainment operating system, is not accessible from the business operating system because the two operating systems are isolated. So, the telephony application executing on the business operating system cannot access the needed state information and it cannot take control over the phone call.
Therefore, a need exists for a method that would allow the sharing of information about the state of a telecommunications session across a plurality of system software images running on the same device.